I recently got the chance to check out the Seattle Museum of Flight, and I am glad that I did. It is amazing how many planes and attractions that they pack in to this museum: They have the grand gallery, that has almost every type of plane imaginable including the SR-17 Blackbird; The Boeing exhibit, that shows how the plane maker got its start; The WWI/WWIII area, that has just about every small great war fighter crammed in to it; The air park with a Concord and an Air Force One for you to walk around in, and last but not least the Space Shuttle Trainer that the astronauts got to train for their missions on.
There are bigger air museums out there, but the Seattle Museum of Flight is very good. It filled me full of wonder around every turn. If you are in Seattle and looking for something to do, The Museum of Flight was more than worth the time and money to check out!